/*
 * Copyright 2002-2014 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.util.exec;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;


/**
 * Used by <code>Execute</code> to handle input and output stream of
 * subprocesses.
 *
 * @author thomas.haas@softwired-inc.com
 */
public interface ExecuteStreamHandler {

    /**
     * Install a handler for the input stream of the subprocess.
     *
     * @param os output stream to write to the standard input stream of the
     *           subprocess
     * @throws IOException Any.
     */
    void setProcessInputStream(OutputStream os) throws IOException;

    /**
     * Install a handler for the error stream of the subprocess.
     *
     * @param is input stream to read from the error stream from the subprocess
     * @throws IOException Any.
     */
    void setProcessErrorStream(InputStream is) throws IOException;

    /**
     * Install a handler for the output stream of the subprocess.
     *
     * @param is input stream to read from the error stream from the subprocess
     * @throws IOException Any.
     */
    void setProcessOutputStream(InputStream is) throws IOException;

    /**
     * Start handling of the streams.
     *
     * @throws IOException Any.
     */
    void start() throws IOException;

    /**
     * Stop handling of the streams - will not be restarted.
     */
    void stop();
}
